Татьяна ***
Решите тригонометрические уравнения
4cos2 x + cos x – 5 = 0
2. 10cos2 x – 17sin x – 16 = 0
3. sin2 x + 6sin x cos x + 8 cos2 x = 0
4. 3 tg x – 6ctg x + 7 = 0
5. 2cos2 x – 11sin 2x = 12
6. 2sin2 x – 3sin 2x – 4cos 2x = 4